Epidemic cholera in the Americas

Cholera returned to the Americas after a 100 year hiatus in Peru in January 1991. Fecal contamination of water caused this epidemic. Even though health authorities informed the public about cholera early in the epidemic holdups to providing safe water permitted its spread. By the end of 1991 there were 391000 cases and 4000 deaths in 15 countries. The use of oral rehydration therapy kept the case fatality rate much lower (1%) than it had been in the past (>20%). This epidemic is a continuation of the 7th cholera pandemic begun in Asia in 1961 with the new Vibrio cholerae 01 El Tor biotype. In Chile the vehicle for transmission of cholera was uncooked vegetables irrigated with raw sewage. Public health authorities forbade the sale of such vegetables and informed the public to cook all vegetables. A decline in the incidence of cholera and typhoid followed these measures. In Ecuador contaminated shellfish spread cholera. US cholera cases were infected in either affected Latin American countries on the airplane returning to the US or from contaminated seafood they brought to the US. Cholera control measures are often difficult to implement. For example the Americas need to invest >US $200 billion over 12 years to provide safe drinking water and adequate sewage disposal. Until funding arrives however governments can repair existing water distribution systems and chlorinate water supplies. In areas not provided with such services authorities can promote use of small mouthed water containers and/or boiling or chlorinated household water. Further health educators can encourage people to wash their hands to cook contaminated foods and to avoid food/beverages prepared by street vendors. Research is accelerating in developing an effective cholera vaccine such as the promising killed whole cell vaccine (subunit B). The epidemic in the Americas is expected to spread to the Caribbean the Amazon Basin and the Atlantic Coast.